By Tyler Clifford NEW YORK (Reuters) – The former head of one of New York City’s police unions was expected to appear in federal court on Wednesday, a source close to the situation said, nearly five months after his resignation in the wake of a federal probe into the labor organization. Ed Mullins, who was first elected president of the Sergeants Benevolent Association (SBA) in 2002, was not in custody early on Wednesday afternoon, though his status could change as the day progresses, the source told Reuters. The hearing is expected to be held at the U.S. District Court for the Southern Distri…